Defect annihilation mechanism in the formation of dodecagonal quasicrystals

TL;DR

This study uncovers the microscopic defect repair mechanisms in dodecagonal quasicrystals, revealing a three-stage process driven by energy gradients that enhances structural stability.

Contribution

It introduces a combined string and spring pair method to determine defect annihilation pathways in quasicrystals using a particle model with Lennard-Jones-Gauss potential.

Findings

Defect annihilation occurs via phason flip, aggregation, and decomposition.

Sequential stages increase structural symmetry during defect repair.

Potential energy gradients drive the defect annihilation process.

Abstract

Understanding defect evolution is essential to the structural stability of quasicrystals, yet the kinetics of defect repair remain poorly understood. Here, by combining the string method and the spring pair method, we determine the minimum energy path from defective to defect-free dodecagonal quasicrystals using a particle model with the Lennard-Jones-Gauss potential. We find that defect annihilation proceeds via three stages: phason flip, aggregation and decomposition of shield-like defects. These sequential transformations are driven by potential energy gradients and accompanied by an increase in structural symmetry. The three stages act synergistically in promoting defect annihilation, offering new insights into the microscopic repair mechanisms of quasicrystals.